I'm using the ADL5380 evaluation board to demodulate an RF signal at its base frequency into IQ channels. I changed the eval board from AC-coupled single-ended configuration to DC-coupled differential outputs for the IQ channels according to the datasheet. Then I recorded the IQ outputs as I changed the phase of the LO signal between 0-360 degrees. I did see oscillations as a function of the phase in both channels. However, the amplitudes of the oscillation were very different. The Q amplitude was about 5x of that in the I channel. I checked the board and the downstream amplifiers and didn't see anything obviously wrong. Then I suspected that the chip might be damaged internally. So I replaced the chip with a brand new one. It was still the same. I wonder if anyone has any clue about what might go wrong. Thanks!